Four people have been killed and dozens more seriously injured after a “violent, fast-moving” fire tore through one of Canada’s busiest military training bases in Alberta, Canada’s prime minister said on Sunday.

Mark Carney called the incident “one of the worst tragedies for the forces on Canadian soil in peacetime”.

The fire and subsequent explosion, which is under investigation, moved quickly because of high winds.

“The nation is in mourning for those brave members of our armed forces whom we have lost. And I have asked the flags on all federal buildings to be flown at half-mast to honour them,” Carney told the nation in an address from Ottawa. “We are praying for the wounded.”

Carney said he had requested a “detailed account” from military officials on the ground about what had happened. The Department of National Defence is expected to provide a technical briefing to reporters later in the day. Emergency crews and military personnel gather at the Wainwright Health Centre on Saturday.

The country’s defence minister, David McGuinty, called it a “terrible incident” as he travelled to the scene to meet senior officials and first responders.

On Saturday night, the defence minister described the situation at CFB Wainwright as “active and delicate” with the fire being monitored very closely. The Department of National Defence said there were no indications that the fire was a terrorist attack.

“I cannot recall an incident like this in recent memory,” McGuinty said, adding that the Royal Canadian Mounted Police (RCMP) were involved in the investigation.

McGuinty did not provide casualty figures or details about what caused the incident and the Canadian armed forces said on Sunday that its “immediate priority” was notifying next of kin and helping those affected by the fire. The armed forces and federal, provincial and local authorities were coordinating the emergency response, they said.

Canada’s top soldier, Gen Jennie Carignan, who serves as chief of the defence staff, called the incident “a profoundly difficult moment for the entire Canadian armed forces”. The nearby community of Wainwright was providing hospital and firefighting support.

The nearby community of Wainwright was providing hospital and firefighting support. Flares were spotted in the sky and military medical paratroopers dropped in on a local school football field.

A doctor at a hospital in the city of Edmonton, 180km (112 miles) north-west of Wainwright, told Canada’s national broadcaster that patients were being brought to hospitals across the city as Wainwright’s healthcare facilities became “completely overwhelmed” by the number of people needing care.

“This number of patients would overwhelm the city of Edmonton,” Dr Warren Thirsk, an emergency department physician at the Royal Alexandra hospital, told CBC News. “It is more patients than any of us want to count right now. It’s a disaster. It’s a one in every 15 to 25-year disaster.”

Officials asked people in Edmonton to avoid the emergency department at the University of Alberta hospital in order to prioritise victims from the military base. Air ambulances were dispatched from Saskatoon and Edmonton.

Canada’s prime minister, Mark Carney, said the nation was ‘in mourning for those brave members of our armed forces whom we have lost’.

In an earlier social media post, Carney said: “A serious incident creating a major fire has occurred at CFB Wainwright, in Alberta. Our thoughts are with all the brave women and men affected.”

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The municipal district of Wainwright said the fire had crossed the base’s fence earlier on Saturday and was spreading rapidly owing to high winds. Firefighters from multiple jurisdictions were responding and no evacuation order was in effect.

Large areas of the province were hit during the day by a windstorm with gusts of up to 100kmh. The wind toppled some trees and sent signs flying and refuse cans rolling down streets.

On Sunday, the Alberta premier, Danielle Smith, described the fire as “heartbreaking” and said it had affected many military personnel.

“On behalf of the government of Alberta, I extend my deepest condolences to the families who have lost loved ones and wish those who have been injured a full recovery. Our thoughts are also with the military personnel, families and colleagues facing uncertainty and grief during this incredibly difficult time,” Smith said. She is due to travel to meet senior officials in Edmonton.

The Saskatchewan premier, Scott Moe, said his province was sending assistance to Alberta but did not specify what resources were being deployed.

CFB Wainwright is one of Canadaa’s busiest military bases.

CFB Wainwright is one of Canada’s busiest military training bases, where soldiers prepare for combat operations. It is home to the Canadian Manoeuvre Training Centre, which conducts realistic battlefield exercises, and the 3rd Canadian Division Training Centre, which provides military training.

The RCMP, speaking on behalf of the military, told reporters a fire was reported at the base in the late afternoon on Saturday and that the blaze had extended beyond the boundaries of the training area.

“On behalf of the Nato military committee, we extend our deepest condolences to the families and loved ones of those who lost their lives in the tragedy at CFB Wainwright, and our wishes for a full recovery to all the injured,” Adm Giuseppe Cavo Dragone, the chair of the Nato military committee, posted on social media. “Those who fell there served our common security, and the military committee will honour their memory.”

Canada’s Conservative leader, Pierre Poilievre, said he had spoken with Carney and the defence minister to offer support to those affected by the fire.

“Pray for Wainwright, everyone,” Poilievre said in a social media post. He urged people in the area to follow emergency instructions and keep roads clear for first responders.